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s Analysis: Nailing Down Metal Tariffs 2. The impact of a tariff Consider a hypothetical example of trade in aluminum between the United States and China. For simplicity, assume that China is the only source o U.S. aluminum imports. The following graph shows the U.S. market for aluminum. Note that in the absence of any trade, the market price for aluminum in the United States is $500 per tonne, and the equilibrium quantity is 150 million tonnes per month. Use the green area (triangle symbol) to show U.S. consumer surplus under free trade with China, and use the purple area (diamond symbol) to sho U.S. producer surplus under free trade with China. 1000 Domestic Demand Domestic Supply A 900 800 Consumer Surplus